To allow embedding a qemu_irq in a struct move its definition to the
header and add a function to init it in place without allocating it.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
---
 hw/core/irq.c    | 25 +++++++++++--------------
 include/hw/irq.h | 18 ++++++++++++++++++
 2 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/hw/core/irq.c b/hw/core/irq.c
index 3f14e2dda7..db95ffc18f 100644
--- a/hw/core/irq.c
+++ b/hw/core/irq.c
@@ -26,16 +26,6 @@
 #include "hw/irq.h"
 #include "qom/object.h"
 
-OBJECT_DECLARE_SIMPLE_TYPE(IRQState, IRQ)
-
-struct IRQState {
-    Object parent_obj;
-
-    qemu_irq_handler handler;
-    void *opaque;
-    int n;
-};
-
 void qemu_set_irq(qemu_irq irq, int level)
 {
     if (!irq)
@@ -44,6 +34,15 @@ void qemu_set_irq(qemu_irq irq, int level)
     irq->handler(irq->opaque, irq->n, level);
 }
 
+void qemu_init_irq(IRQState *irq, qemu_irq_handler handler, void *opaque,
+                   int n)
+{
+    object_initialize(irq, sizeof(*irq), TYPE_IRQ);
+    irq->handler = handler;
+    irq->opaque = opaque;
+    irq->n = n;
+}
+
 qemu_irq *qemu_extend_irqs(qemu_irq *old, int n_old, qemu_irq_handler handler,
                            void *opaque, int n)
 {
@@ -69,10 +68,8 @@ qemu_irq qemu_allocate_irq(qemu_irq_handler handler, void *opaque, int n)
 {
     IRQState *irq;
 
-    irq = IRQ(object_new(TYPE_IRQ));
-    irq->handler = handler;
-    irq->opaque = opaque;
-    irq->n = n;
+    irq = g_new(IRQState, 1);
+    qemu_init_irq(irq, handler, opaque, n);
 
     return irq;
 }
diff --git a/include/hw/irq.h b/include/hw/irq.h
index 645b73d251..c861c1debd 100644
--- a/include/hw/irq.h
+++ b/include/hw/irq.h
@@ -1,9 +1,20 @@
 #ifndef QEMU_IRQ_H
 #define QEMU_IRQ_H
 
+#include "qom/object.h"
+
 /* Generic IRQ/GPIO pin infrastructure.  */
 
 #define TYPE_IRQ "irq"
+OBJECT_DECLARE_SIMPLE_TYPE(IRQState, IRQ)
+
+struct IRQState {
+    Object parent_obj;
+
+    qemu_irq_handler handler;
+    void *opaque;
+    int n;
+};
 
 void qemu_set_irq(qemu_irq irq, int level);
 
@@ -23,6 +34,13 @@ static inline void qemu_irq_pulse(qemu_irq irq)
     qemu_set_irq(irq, 0);
 }
 
+/*
+ * Init a single IRQ. The irq is assigned with a handler, an opaque data
+ * and the interrupt number.
+ */
+void qemu_init_irq(IRQState *irq, qemu_irq_handler handler, void *opaque,
+                   int n);
+
 /* Returns an array of N IRQs. Each IRQ is assigned the argument handler and
  * opaque data.
  */
-- 
2.30.9

On Sat, 29 Jun 2024 at 21:01, BALATON Zoltan <balaton@eik.bme.hu> wrote:
>
> To allow embedding a qemu_irq in a struct move its definition to the
> header and add a function to init it in place without allocating it.
>
> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>

Yes, I think this makes sense, and I'm not quite sure
why we don't support it already (probably just historical
inertia -- the qemu_irq APIs were written before QOM
and when the whole design was oriented around an
"allocate and return a pointer" style rather than
allowing for embedding structs).

-- PMM